Method of tilling with improved draft connection

ABSTRACT

A tractor includes front wheels and rear wheels. A three-point hitch connects a yoke to the tractor. The yoke is stabilized by stabilizer arms which are connected under the rear tractor axles and to the frame of the tractor forward of the rear tractor axles. The stabilizer arms lock up the yoke so that it is rigidly fixed to the tractor when an earth working implement tilling the soil is stressing the yoke. The stabilizer arms are connected to the yoke by chain links which permit the yoke to be raised and lowered by the three-point hitch, but which prevent any lateral movement or flexibility to the yoke. This rigidity in part is by having the chain link connection of each stabilizing link straddle the connection of the three-point hitch to the yoke. In addition, the two stabilizing arms are connected by a cross brace which is bolted in place. The cross brace may be unbolted in the event a power takeoff shaft is to be used, which would otherwise be blocked by the cross brace.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a division of the prior patent application entitled, "DRAFTCONNECTION", Ser. No. 07/331,454, Mar. 31, 1989, issued as U.S. Pat. No.4,905,769, Mar. 6, 1990; which was itself a continuation-in-part of theprior application entitled, "DRAFT CONNECTION", Ser. No. 06/925,162,Oct. 31, 1986, issued as U.S. Pat. No. 4,860,833, Aug. 29, 1989; whichwas itself, a continuation-in-part of prior application entitled,"TRACTOR STABILIZER", Ser. No. 06/754,619, July 12, 1985, issued as U.S.Pat. No. 4,655,295 Apr. 7, 1987. All of the inventors of thoseapplications are co-inventors of this application, the present ownershipof the issued patents are all the same as the ownership of thisapplication.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

This invention relates to earth working, and more particularly toagriculture tillage. Farmers have ordinary skill in the art to whichthis invention relates.

(2) Description of the Related Art

For many years, farm tractors have been used to draft tillage equipment,and particularly heavy tillage equipment, through fields By heavytillage equipment, it is meant tillage equipment that tills the soildeeply, e.g., over 3". Besides turning plows and rippers, listers arecommon type of such equipment.

Because agricultural development in the United States and the increasedlabor costs, extremely large tractors are used so that only one farmercan till large areas of land. As used herein, a large tractor means atractor having over 45 horse power. At a time when labor costs wereless, it was economically feasible to use small tractors. Now, the useof smaller tractors is prohibitively expensive because each tractorrequires a human operator. Therefore, for many years, the trend inUnited States agriculture has been to use larger and larger tractors.The tool bars are long and equipped with gauge wheels. A wide strip orswath of ground is tilled with each pass of the tractor.

Typically, these large tractors have low pressure pneumatic tires. Asthe power of the tractor increases, it is necessary to increase theweight for sufficient traction upon the soil to draft the heavy tillageequipment through the earth. To prevent undue compaction of the groundunder the wheels, extremely large tires with low air pressure are usedto distribute the weight of the tractor over a large area.

However, large tires with low air pressure results in a lack of lateralstability. The frame of the tractor tends to move back and forthlaterally even though the tread of the tires follows the earthfaithfully. The tires themselves permit the wheels, and thus the frames,to move laterally.

Farmers have always had difficultly plowing straight furrows. Surfaceindentation, rocks, clods, clumps of weeds, grasses and roots, steeringcorrections, and other causes of lateral shifts, jumps, jerks, andwiggles the implement seems uncorrectable with prior art equipment. Infact, a lateral sway was designed into the hitch (Morling, pages 7 and11). (Roy W. Morling, Agricultural Tractor Hitches Analysis of DesignRequirements, No. 5, Dec. 12, 1979, published by ASAE, P.O. Box 410, St.Joseph, Mich. 49085) A copy of this publication is available in thePatent Office file of our prior patent application, Ser. No. 07/925,162.The soft tires tend to aggravate the problem. Also, with long tool bars,plows on one end may be plowing in hard soil while plows on the otherend are plowing in soft soil.

It has long been known in the design of draft vehicles, such as farmtractors, that the equipment might be drafted from the frame of thetractor forward of the rear axles. Examples of such drafting apparatusinclude the French patent to GUILLOTTE, Pat. No. 1,098,133, "publie"July 18, 1955 or the U.S. Pat. No. 2,713,295 to SILVER ET AL. Also, seepage 4 of Morling. Although the drafting from this position seemsadvantageous, applicants have difficulty explaining why thisadvantageous result came about. The only publication they found thatseemed to discuss the problem was Morling and the publication by Gilland Berg, "Soil Dynamics in Tillage and Traction" by William R. Gill andGlen B. Vanden Berg, a publication of the Agricultural Research Serviceof the United States Department of Agriculture, United States PrintingOffice, 1967. Pages 340-342, 364-365, 416-421, and 511 of thispublication are available in the Patent Office file of our prior patentapplication, Ser. No. 07/925,162. Applicants have provided thehighlighting.

Gill and Berg indicate at page 340 the efficiency of power transmissionfrom the rear axle through the tires into tilled or agricultural soil isperhaps no better than 50 percent (as applicants understand thediscussion).

About 1950, the great advantages of the three point hitches werecommercially recognized. Three point hitches are shown in the U.S. Pat.No. 4,142,588 issued to DOSS, Mar. 6, 1979; ALTGELT, U.S. Pat. No.2,637,262, May 5, 1953; and ANDERSON, U.S. Pat. No. 2,797,627, July 2,1957, for example. These three point hitches have the great advantage ofproviding quick attachment and detachment of implements to farmtractors. The three point hitch made it possible for one man to quicklydetach one implement and attach another. Also, see page 6 of Morling.Because of the great advantages of the three point hitch, tractormanufacturers quit manufacturing tractors with equipment drafted fromthe frame forward of the rear axle. Many three point hitches includeforces sensing and load control features. Morling concludes that thesefeatures are not economically beneficial for large tractors (pages 17,18, and 27). Energy losses are explained on page 18.

In recent years, quick couplers or quick hitch frames have become widelyused. (Morling, page 21) The quick hitch frame is a yoke or frame whichis attached to the ends of the three links of the three point hitch. Therear of the yoke or frame contains hooks which may readily be hookedonto horizontal bolts and pins by which the agricultural implementswould otherwise be hooked to the distal points of the three links.

Farm tractors or tractors for agricultural use are normally not singleuse vehicles. Although it has been described as primarily being used todraft heavy tillage equipment, it will also be understood that atvarious times they are used to draft equipment requiring a power takeoffshaft from the engine of the tractor to the towed implement. In additionto this, often times, the towed implement will be connected by a trailerhitch or the trailer itself might be connected.

The design of the tractors is such that the power takeoff and trailerhitch sometimes would interfere with the cross bracing of the hitch asshown in the application of Ser. No. 06/925,162 indicated above.

The rear three point hitch tends to lift the front of the tractor offthe ground during certain conditions. It was often sought to correctthis problem by use of counterweights at the front of the tractor.

RUDD, U.S. Pat. No. 3,749,421, issued June 31, 1973, discloses armswhich extend from bearings on the rotating axle outboard of the rearlarge tractor tires. These are connected to a tool bar or an elongateddraw bar. The tractor lift arms are connected to the draw bar by pivotblocks 54.

The following patents are of record in the parent application (some arediscussed above).

    ______________________________________                                        U.S. Pats.                                                                    ______________________________________                                        MCCALL                984,581                                                 PLUM                  1,608,666                                               HESTER                2,019,854                                               THEIS                 2,197,670                                               WATSON                2,496,760                                               ALTGELT               2,637,262                                               SILVER ET AL          2,713,295                                               RUDIO                 2,752,838                                               ANDERSON              2,797,627                                               NEEDHAM               3,021,621                                               STEFFE                3,601,202                                               RUDD                  3,749,421                                               CAPEHART              3,840,076                                               QUANBECK              4,068,723                                               BUCK ET AL            4,069,874                                               LARSON                4,117,889                                               DOSS                  4,142,588                                               WILLIAMS              4,331,345                                               ______________________________________                                        French Patent                                                                 ______________________________________                                        GUILLOTTE             1,098,133                                               ______________________________________                                    

These patents are considered pertinent because the applicant believesthe Examiner would consider anything relevant or pertinent to the parentapplication to be relevant to the examination of this application.

SUMMARY OF THE INVENTION

(1) Progressive Contribution to the Art

We have discovered that, if the prior method of drafting forward of therear wheels from under the frame of the tractor is combined with thethree point hitch, according to our invention, many advantages result.

First, applicants find that the lateral shifting of the tractor andtillage implement is eliminated or at least greatly reduced. Therefore,straight rows are plowed.

Second, applicants find that the drafting capabilities of the tractorare greatly improved with less tire slippage. The tractor engine doesnot surge.

Third, there is better weight distribution between the front and rearwheels. The plow depth is constant.

Fourth, the convenience of the quick implement change and the controlobtained by the three point hitch is retained.

Fifth, if the individual bars are laterally rigidly connected to theyoke or quick hitch frames, some of the bracing can be removed toprovide a passageway for power takeoff shafts or trailer hitches.

As discussed in our prior application Ser. No. 06/925,162; theadvantages of better drafting and increased fuel consumption are notfully understood. Reference is made to that discussion and to thefurther discussion in Gill and Berg on page 416 concerning this.

Basically, the design of this invention is characterized by the threepoint hitch combined with the connection forward of the rear wheels byhaving the draft arm connected as a stabilizing frame which extendsrearwardly from below the rear axles to connect to a quick hitch frame(hereafter called a yoke). The yoke is connected by a conventional threelink connection. The stabilizing arms have a short chain link betweenthe rear end of the stabilizing arms and the yoke so that the axis ofthe stabilizing arm is actually below the bolt to which the chain linkis attached to the yoke. In one embodiment of this application, thestabilizing arm is bifurcated at the rear so that on each side, twochain links are used. By having two chain links in the biforcatedfashion, greater rigidity results.

The connection, as described, results in extremely rigid connectionbetween the plows and the tractor. Wherein the prior art taught thatthere should be some sway and lateral movement as well as verticalmovement, it is the teaching of this application that while plowing, theplows should be fixed to the tractor in one rigid position and that allpossible motion, flexibility, or movement between the tractor and theplow eliminated.

With the rigidity obtained by the bifurcated stabilizing arm, it is notessential for improved performance to have a cross brace from onestabilizing arm to the other. Through empirical tests, we have foundthat the improved performances over the prior art is obtained withoutthe cross brace. However, we have also found with the cross brace inplace, there is even better performance; and therefore, unless theconvenience of being able to quickly shift from a power takeoff ortrailer hitch operation to a heavy tillage operation is desired, it ispreferable that the brace be retained. However, in the event theindividual operator desires to have the convenience to be able tomaintain the equipment with the power takeoff or trailer hitch in place,the center brace should be bolted in place so that it may be readilyremovable for this changed operation.

(2) Objects of this Invention

An object of this invention is to till agricultural fields.

Another object of this invention is to provide a hitch which can quicklybe detached from heavy tillage equipment to be used with equipmentrequiring a power takeoff from the tractor.

Further objects are to achieve the above with devices that are sturdy,compact, durable, lightweight, simple, safe, efficient, versatile,ecologically compatible, energy conserving, and reliable, yetinexpensive and easy to manufacture, install, adjust, operate andmaintain.

Other objects are to achieve the above with a method that is rapid,versatile, ecologically compatible, energy conserving, rapid, efficient,and inexpensive, and does not require highly skilled people to install,adjust, operate, and maintain.

The specific nature of the invention, as well as other objects, uses,and advantages thereof, will clearly appear from the followingdescription and from the accompanying drawing, the different views ofwhich are not scale drawings.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a side elevational view of a farm tractor with an embodimentof this invention. Parts have been broken away and one wheel removed forclarity.

FIG. 2 is a bottom plan view of the rear of the tractor showing theinvention.

FIG. 3 is an exploded perspective view of the axle clamp and pivotbeneath the axle.

FIG. 4 is a front sectional view of the axle clamp.

FIG. 5 is a perspective view of the connection of the draft links to theyoke, with the cross brace removed.

FIG. 6 is a top sectional view of the draft connection pin area of theyoke taken substantially on line 6--6 of FIG. 5, with the cross braceremoved.

FIG. 7 is is a rear elevational view of the connected yoke without animplement attached, showing the power take off shaft.

FIG. 8 is a sectional view of the cross brace taken substantially online 8--8 of FIG. 7.

As an aid to correlating the terms of the claims to the exemplarydrawing, the following catalog of elements and steps is provided:

10 frame

11 beams

12 engine

14 front wheels

15 front axle

16 rear wheels

17 transmission means

18 rear axle

20 axle housing

21 power takeoff shaft

22 differential housing

23 transmission housing

24 tillage or earth working implement

25 plow

26 tires

28 lift draw arm or draft link

29 pins

30 distal end

32 top arm or link

34 top distal end

36 yoke

37 yoke legs

38 pin or shaft

40 draft hooks

41 top hook

42 implement pins

44 lift arms

46 lift shaft

48 lift connecting rod

50 draw pins

52 stabilizer draw arm or auxiliary draw link

53 rear end of arms

54 connection

56 axle clamp

58 belly plates

62 frame draw arm or pitman

64 belly pin

66 key

68 pivot

74 bushing

76 pivot bolt

110 cross arm

112 flat plate (fitting)

114 medial end

116 cross brace

118 flat plate

120 bolt holes

122 bolts

124 chain link units

126 chain link

128 bushing

134 web

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings, there may be seen a typical agriculturaltractor. Basically, the tractor will include frame 10 Spaced apart framebeams 11, upon which is mounted engine 12, form a portion of the frame(FIGS. 1 and 2). The tractor is guided by turning front wheels 14mounted upon the front axle 15. The engine is connected throughtransmission means 17 to rear wheels 16 which are mounted upon axle 18in axle housing 20. The axle housing is rigidly attached to differentialhousing 22. The differential housing is rigidly attached to transmissionhousing 23. The differential housing 22 and transmission housing 23 areconsidered part of the transmission means 17. The frame beams 11 areparallel and the extend from the front axle 15 to the transmissionhousing 23. The frame beams 11 are parallel to the tractor axis and thedirection of draft. The entire frame includes not only the beams 11 butalso the transmission housing 23, differential housing 22, and rear axlehousing 20. The front axles 15 and rear axles 18 might also beconsidered part of the frame 10.

Power takeoff shaft 21 extends from the differential housing 22. As seenin the drawings, the power takeoff shaft is along the center line of thetractor.

Although the frame beams 11 of the tractor are heavy beams, analysis ofthe stresses which are imposed upon the frame 10 will show that theframe has a certain amount of flexibility. This flexibility or stain ismeasured in fractions of inches. The extreme forces or stress of theengine 12 drafting tillage implement 24 with plows 25 will result inmeasurable strain in the frame 10 and frame beams 11. There will be somevibration in the frame.

As discussed before, the rear wheels 16 normally have large low pressurepneumatic tires 26 mounted upon them.

The normal three point hitch includes two lift draw arms or draft links28, each of which is pivoted by pins 29 to the lower portion of thedifferential housing 22 and extends rearwardly and outwardly to a distalend 30. It will be noted that the draw lift links are pivoted to thedifferential housing 22 by horizontal pins 29 which are in about foreand aft alignment with the outside of the frame beams 11. In thisapplication, the distal end 30 of each of the lift links 28 will be atthe same level as the other and spaced apart. Top arm or link 32 extendsfrom the center of the upper portion of the differential housingrearwardly and terminates at the top distal end 34.

Quick hitch yokes 36 are commercially available on the market and widelyused. The yoke 36 includes a rectangular frame with a connection at top35 for the top distal end 34. Two legs 37 depend from each side of thetop 35 with connections at the lower end for the distal ends 30 of thelift draw links 28. These connections of the distal ends are normally bythe use of pin 38. The quick hitch yoke 36 will usually be in a verticalplane transverse the direction of draft.

The rear of the yoke 36 has two upward open draft hooks 40 immediatelybehind the distal end 30 of the lift draw arm. Top hook 41 isimmediately behind the top distal end 34. Therefore, the tillageimplement 24 with earth working plows 25 can readily be connected intothese hooks 40 and 41, inasmuch as the implement has correlatingimplement pins 42 which are designed and placed to mate with the hooks40 and 41.

Two lift arms 44 are mounted upon the upper portion of the differentialhousing 22. They are pivoted by lift shaft 46 which is connected to amechanism within the differential housing 22. It will be noted that thelift arms 44 are attached to the lift shaft 46 in approximate alignmentwith the outside surfaces of the frame beams 11. Lift connecting rod 48connects the end of each lift arm 44 to one of the lift draw links 28near, but spaced forward of its distal end 30. Therefore, it can be seenthat by raising or lowering the lift arms 44, the lift draft links; andtherefore, the quick hitch yoke 36 is raised and lowered, as is thetillage implement 24 with the plows 25 connected thereon. The lift arms44 sometimes have exterior hydraulic cylinders attached to them. Also,often there is an optional automatic load and depth control connected tothe lift arms 44 (See Morling).

As explained above, the structure defined to this point is well knownand commercially available on the market. Tractors with equipment likethis have been widely sold in the United States.

According to the invention of our previous application, axle draw pins50 are connected under the axle housing 20 outboard of the point ofconnection of the lift draw links 28. The distance from the center ofthe tractor to each axle draw pin 50 is about the same as, or a littlemore than, the distance from the center of the yoke to each of thedistal ends 30. The distance from the connection of the draft links 28at their connection pins 29 to the differential 22 to the draw pins 50is about the same as the distance between the pins 29 themselves. I.e.,the distance from one draw pin 50 to the other opposite draw pin 50 isabout three times the distance between the pins 29. Stated otherwise,the distance between the draw pins 50 is about three times the length ofthe lift shaft 46.

Stabilizing or auxiliary draw arm or link 52 extends from the draw pin50 to the yoke 36 at the rear end 53 of the stabilizing draw arm 52.Connection 54 at the rear end 53 attaches to the yoke 36. The draw pins50 are through axle clamps 56 which are clamped one to each end of theaxle housing 20 (FIGS. 1, 3 and 4). The draw pins 50 are normal to thedirection of draft and parallel to the rear axle 18.

Belly plates 58 depend from the frame 10 of the tractor forward of therear axle. Specifically, they depend from the frame beams 11. The bellyplates will be attached to the beams 11 preferably by bolting to theoutside surfaces thereof. The belly plates will be located aboutone-half the way between the front axle 15 and the rear axle 18. I.e.,the distance from the belly plate on the frame beam to the rear axle 18is within about 10% or 20% of the midpiont between the front axle andthe rear axle. E.g., in one instance the distance from the front axle torear axle is 114" and the distance from the rear axle to the belly plateis 62".

Frame draw arm 62 extends from belly pin 64 in the belly plate 58 to theaxle or draw pin 50, which is mounted on the axle clamp 56 below theaxle housing 20. Inasmuch as both the frame draw arm or pitman 62 andthe stabilizer draw arm or auxiliary draw link 52 are connected to thedraw pin 50 mounted on the axle clamp 56 below the axle housing 20,there is a minimal amount of stress upon the axle housing 20. Asexplained before, although the parts of the tractor are heavy steelparts, yet, there will be a certain amount of flexibility to them. Also,there will be some tolerance in the holes in the ears of the clamp 56.Therefore, the draft from the belly plate 58 to the yoke connection 54will be from the belly plate 58 and not from the axle housing 20.

When the tillage implement 24 is raised or lowered, the stabilizing arm52 will pivot about the draw pins 50, and the draw pins 50 will providea certain amount of stabilization through the axle housing 20. However,the main stress is transmitted to the tillage equipment through thequick hitch yoke 36 from the belly plates 58.

It is preferred that the frame draw arm 62 be level for best operation.Satisfactory operation can be had with the pin 64 higher or slightlylower than the axle pin 50.

It will be noted from the drawing that the lift draw arm or draft link28 is attached to the differential housing 22 by pin 29 which is locatedto the rear and below the draw pin 50. The distal end 30 of the drawlink 28 is connected by the pin or shaft 38 which extends from theoutboard of the yoke 36 on each end. The shaft 38 is rotatable in theyoke 36. The end of the stabilizer arm or auxiliary draw link 52connects to the shaft pin 38.

The structure described to this point is basically the structure definedin the prior application indentified above.

Cross arm 110 is attached at the rear end 53 of the stabilizer draw arm52. A gusset makes the cross arm 110 rigid with the stabilizing draw arm52. The cross arm is at right angles to or normal to the direction ofdraft. Flat plate 112 or fitting is attached to the medial end 114 ofthe cross arm. The fitting 112 also could be considered to be attachedor connected to the stabilizer draw arm 52 at the rear end 53. Thefitting 112 is attached to each of the stabilizer draw arms.

Cross brace 116 has flat plate 118 on each end thereof. Each of the flatplates 112 and 118 have four bolt holes 120 therethrough. Bolts 122extend through the bolt holes to securely fasten the plates togetherwhich, in effect, forms a rigid unit of the two stabilizer draw arms 52.However, as pointed out above, the bolts 122 may be removed and thecross brace 116 be removed in the event the farmer is using an implementrequiring power takeoff 21 or the like.

With the reduction of the bracing between the stabilizer shafts, it isdesirable to more rigidly fix the stabilizer draw arms 52 to the yoke 36in the lateral direction. This is accomplished by making the connection54 in the form of two chain link units 124 on each stabilizer draw arm.The two chain link units 124 could also be described as connection meansfor stabilizing the agricultural implement from the stabilizer drawarms, raising and lowering the stabilizer arms by the lift arms, andpreventing lateral movement of the implement relative to the stabilizerarms. It will be noticed that the connection means or chain link units124 straddle the connection 30 of the lift draw arms 52 to the yoke 36.

Thus by the locking of the chain links the tillage implement is rigidlyfixed to the tractor while tilling the soil.

There is a separate shaft 38 for each of the stabilizer arms 52 or eachof the legs 37 of the yoke. Each chain link unit 124 will include twochain links 126 which are connected by bushing 128. The bushing 128 willtelescope over the shaft 38. The shaft is held by key 66 at each end.Bushing 74 is connected to the rear end 53 of the stabilizer draw arm.As shown, there will be one bushing 74 at each end of the cross arm 110.The chain links 126 will straddle the bushing 74 and be held in place bybolt pivot 68.

To increase the rigidity of the connection of the stabilizing draw armto the yoke, web 134 is connected between the two individual chain links126 and welded securely to them as well as to the bushing 128.

The embodiment shown and described above is only exemplary. We do notclaim to have invented all the parts, elements or steps described.Various modifications can be made in the construction, material,arrangement, and operation, and still be within the scope of ourinvention.

The restrictive description and drawing of the specific examples abovedo not point out what an infringement of this patent would be, but areto enable one skilled in the art to make and use the invention. Thelimits of the invention and the bounds of the patent protection aremeasured by and defined in the following claims.

We claim as our invention:
 1. The procedure for tilling agriculturalland with an agricultural tractor havinga. a differential housing towhich a rear axle housing is connected, b. rear wheels journaled to theaxle housing, c. large low pressure tires on the rear wheels, d. a frontaxle, e. front wheels on the front axle, f. two spaced apart frame beamsextending rearward from the front axle, g. an engine on the frame beams,h. transmission means on the tractor for transmitting power from theengine to the rear wheels, i. a transmission housing interconnecting theframe beams and the differential housing, j. a quick hitch yoke in theform of a vertical frame, k. said yoke including three hooks, two drafthooks at the same level and spaced apart, and a top hook above andbetween the draft hooks, l. two draft links, m. each draft link pivotedto the yoke immediately forward a draft hook, each draft link pivoted tothe differential housing, n. a top link connected from the yokeimmediately forward of the top hook and extending to the differentialhousing, o. an earth working implement having three bolts, p. said threebolts located in said three hooks to quickly attach and detach the earthworking implement to the quick hitch yoke, q. the improved method oftilling the soil comprising: r. at least partially drafting the earthworking implement through the yoke from the frame beams forward of thetransmission means, and s. rigidly fixing horizontally and verticallythe earth working implement to the tractor while tilling the soil. 2.The invention as defined in claim 1, further comprising:t. twostabilizing draw arms for partially drafting the earth working implementforward of the transmission means and also for rigidly fixing the earthworking implement, and u. said method further comprising: v. rigidlycross bracing said stabilizing draw arms to each other.
 3. The inventionas defined in claim 1, further comprising:t. a power takeoff shaftextending rearwardly from said transmission means, and u. twostabilizing draw arms for partially drafting the earth working implementforward of the transmission means and also for rigidly fixing thetillage implement, and v. said method further comprising: w. rigidlycross bracing said stabilizing draw arms to each other for more rigidlyfixing the earth working implement, and x. removing said cross bracingfor extension of said power takeoff shaft.
 4. The invention as definedin claim 1 further comprising:t. two stabilizing draw arms for partiallydrafting the earth working implement forward of the transmission meansand also, u. wherein the earth working implement is rigidly fixed to thetractor by locking chain links to said stabilizing draw arms, the earthworking implement being connected to said chain links.